CN220995399U - Special screw rod is extruded to medical pipe of polyurethane medical treatment - Google Patents
Special screw rod is extruded to medical pipe of polyurethane medical treatment Download PDFInfo
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- CN220995399U CN220995399U CN202322049529.XU CN202322049529U CN220995399U CN 220995399 U CN220995399 U CN 220995399U CN 202322049529 U CN202322049529 U CN 202322049529U CN 220995399 U CN220995399 U CN 220995399U
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- 229920002635 polyurethane Polymers 0.000 title claims abstract description 30
- 239000004814 polyurethane Substances 0.000 title claims abstract description 30
- 230000006835 compression Effects 0.000 claims abstract description 38
- 238000007906 compression Methods 0.000 claims abstract description 38
- 229920003023 plastic Polymers 0.000 claims abstract description 21
- 239000004033 plastic Substances 0.000 claims abstract description 21
- 239000007787 solid Substances 0.000 claims abstract description 11
- 230000004888 barrier function Effects 0.000 claims abstract description 5
- 238000000926 separation method Methods 0.000 claims description 21
- 238000007599 discharging Methods 0.000 claims description 4
- 238000001125 extrusion Methods 0.000 claims 5
- 239000013078 crystal Substances 0.000 abstract description 4
- 238000013461 design Methods 0.000 abstract description 4
- 238000010924 continuous production Methods 0.000 abstract description 3
- 230000000694 effects Effects 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 11
- 238000010008 shearing Methods 0.000 description 7
- 238000002844 melting Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- 239000002994 raw material Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000012768 molten material Substances 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
Landscapes
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
The utility model provides a special screw rod is extruded to medical pipe of polyurethane, including screw rod and main flight, main flight sets up on the face of cylinder of screw rod along screw rod length direction, main flight forms helicoidal groove and main spiral shell limit with the screw rod, the screw rod is divided into feeding section along length direction from feeding to ejection of compact in proper order, separate compression section, the metering section, the mixing section, second order compression section and second order metering section, main spiral shell limit on the screw rod is equal, be equipped with a pair flight that plays barrier effect with solid plastic and molten plastic separately on separate compression section, the external diameter of pair flight is less than main flight, the screw diameter of separate compression section increases gradually, the draw ratio of screw rod 27:1 ~ 29:1. The utility model has reasonable structural design, ensures that polyurethane plastic can be fully sheared and melted in the screw by changing the screw structure, ensures that the product has no crystal point, glossiness and uniform thickness, simultaneously increases the stability of continuous production quality and improves the product quality.
Description
Technical Field
The utility model belongs to the technical field of high polymer material processing machinery, relates to a screw structure of an extruder, and particularly relates to a special screw for extruding a polyurethane medical catheter.
Background
The extruder is used for fully mixing and extruding one or more granular raw materials and outputting the raw materials, and is mainly used in the field of plastic or rubber manufacturing. The medical polyurethane (TPU) catheter extruder is characterized in that dried polyurethane (TPU) plastic enters a containing cavity between a screw and a machine barrel through a blanking port of the extruder, a bevel surface rotating through the screw generates thrust vertical to the bevel surface to the plastic, the plastic is pushed forward, in the pushing process, the material is melted under the heating of the machine barrel, the shearing and compression effects brought by the screw, the melted plastic enters a machine head through a porous plate from the machine barrel, passes through a mouth die to form a continuous body with the cross section similar to the shape of the mouth die, then the continuous body is cooled, the raw material with a certain geometric shape and size is changed into a high-elastic state from a viscous state, and finally the raw material is cooled and shaped into a glass state, so that the required catheter product is obtained. If the screw structure is too simple or unreasonable, the plasticization of polyurethane (TPU) is incomplete, the surface of the pipe is uneven, and the pipe has crystal points, so that the product quality and the productivity are reduced, the machine, factory building and manual utilization rate are low, and the competitive advantage is lost.
Through investigation, the Chinese patent with the prior patent number of CN202320050219.7, namely a special screw for a polyurethane casting film extruder, comprises a screw and is characterized in that: the screw rod is sequentially divided into a feeding section, a compression section, a first metering section, a barrier section, a second metering section and a mixing section along the length direction from feeding to discharging, screw threads are arranged on screw rod cylindrical surfaces of the feeding section, the compression section, the first metering section and the second metering section along the length direction, the screw threads and the screw rods form screw grooves and screw edges, the screw grooves and the screw edges are formed by the screw threads, the screw grooves and the screw edges are identical in screw edge screw pitch, the length of the compression section is larger than that of the feeding section, the screw grooves and the screw grooves are gradually shallower in the screw edge screw pitch, the screw groove and the screw grooves are leveled in depth ratio of the screw rods is 29:1-31:1, and the screw rod diameter phi is 55-phi 180mm. The screw rod can enable polyurethane plastics to be sufficiently sheared and melted in the screw rod, has the characteristics of sufficient shearing and melting and high plasticizing rate, but is specially aimed at extruding a polyurethane casting film, and cannot be completely suitable for extruding a polyurethane (TPU) medical catheter, so that a special screw rod for extruding the polyurethane medical catheter needs to be designed to meet production requirements.
Disclosure of Invention
The utility model aims to solve the technical problems of providing a special screw for extruding a polyurethane medical catheter aiming at the current technical situation, and has the characteristics of reasonable structural design, sufficient melting plasticization of materials in the screw and good extruding effect.
The technical scheme adopted for solving the technical problems is as follows: the utility model provides a special screw rod is extruded to medical pipe of polyurethane medical treatment, includes screw rod and main flight, and main flight sets up on the face of cylinder of screw rod along screw rod length direction, and main flight forms helicoidal groove and main spiral arris, its characterized in that with the screw rod: the screw is sequentially divided into a feeding section, a separation type compression section, a metering section, a mixing section, a second-order compression section and a second-order metering section along the length direction from feeding to discharging, the main screw pitch on the screw is equal, a secondary screw slice which plays a barrier role to separate solid plastic from molten plastic is arranged on the separation type compression section, the outer diameter of the secondary screw slice is smaller than that of the main screw slice, the screw diameter of the separation type compression section is gradually increased, and the length-diameter ratio of the screw is 27:1-29:1.
As improvement, the auxiliary spiral piece divides the spiral groove of the separation type compression section into a molten state area spiral groove and a solid state area spiral groove, molten plastic enters the molten state area beyond the outer diameter of the auxiliary spiral piece, the width of the solid state area spiral groove is gradually narrowed, the depth of the spiral groove is gradually shallower, the width of the molten state area spiral groove is gradually widened, and the depth of the spiral groove is gradually deepened and then shallower and is leveled with the depth of the spiral groove of the metering section.
Further, a plurality of longitudinal grooves are formed in the cylindrical surface of the screw rod of the mixing section at equal intervals, the longitudinal grooves are divided into two groups of feed grooves and discharge grooves, the two groups of longitudinal grooves are arranged alternately, wherein the outlet of the feed grooves is closed in the axial direction, and the inlet of the discharge grooves is closed in the axial direction.
Still further, the outside diameter of the thread between the feed chute and the discharge chute is less than the screw diameter.
Further, the screw groove depth of the second-order compression section gradually becomes shallow and is leveled with the screw groove depth of the second-order metering section.
Further, the grooves of the second-order metering section are equal in depth.
Further, the length of each section on the screw is as follows: the feeding section is larger than the separation type compression section, the second-order metering section is larger than the second-order compression section, the mixing section is larger than the metering section, the length of the feeding section is 30-40% of the total length of the screw, the length of the separation type compression section is 24-28% of the total length of the screw, and the length of the metering section is one lead.
Finally, the aspect ratio of the screw 28:1, the diameter phi of the screw rod is 20-50 mm.
Compared with the prior art, the utility model has the advantages that: carry out reasonable design to the structure of screw rod, adopt 28:1 length-diameter ratio of the screw rod, so that the polyurethane plastic can be fully melted and plasticized in the screw rod; the separation type compression section is arranged, and the auxiliary spiral piece is arranged on the separation type compression section, so that a material is melted in a molten state in the screw, and a solution containing unmelted solid small particles is subjected to high shearing to be melted when flowing to the external diameter of the auxiliary spiral piece, thereby improving the melting rate; setting a mixing section to enable the solvent of small unmelted solid particles to be subjected to shearing action, melting and plasticizing, and enabling the unmelted material in the melted material to be tiny and uniform through shearing and mixing; and setting a second-order compression section and a second-order metering section to plasticize the molten material again. The utility model has reasonable structural design, ensures that polyurethane plastic can be fully sheared and melted in the screw by changing the screw structure, ensures that the product has no crystal point, glossiness and uniform thickness, simultaneously increases the stability of continuous production quality and improves the product quality.
Drawings
Fig. 1 is a schematic structural diagram of an embodiment of the present utility model.
Detailed Description
The utility model is described in further detail below with reference to the embodiments of the drawings.
As shown in figure 1, the special screw for extruding the polyurethane medical catheter comprises a screw 1 and a main screw piece 2, wherein the main screw piece 2 is arranged on the cylindrical surface of the screw 1 along the length direction of the screw 1, the main screw piece 2 and the screw 1 form a screw groove and a main screw edge, the screw 1 is sequentially divided into a feeding section A, a separation type compression section B, a metering section C, a mixing section D, a second-order compression section E and a second-order metering section F along the length direction from feeding to discharging, the main screw edge distance on the screw A is equal, a secondary screw piece 3 which plays a barrier role to separate solid plastic from molten plastic is arranged on the separation type compression section B, the outer diameter of the secondary screw piece 3 is smaller than that of the main screw piece 2, the diameter of the screw 1 of the separation type compression section B is gradually increased, the secondary screw piece 3 divides the screw groove of the separation type compression section B into a molten state region screw groove 3.2 and a solid state region screw groove 3.1, the width of the solid state screw groove 3.1 gradually becomes narrower, the screw groove depth gradually becomes shallower, and the screw groove depth gradually becomes deeper and deeper. The Polyurethane (TPU) plastic is melted in a molten state in a screw, and a solution stream containing unmelted solid small particles is subjected to high shear to melt when reaching a separation type, so that the melting rate is improved.
A plurality of longitudinal grooves 4 are formed in the cylindrical surface of the screw 1 of the mixing section D at equal intervals, the longitudinal grooves 4 are divided into two groups of feed grooves and discharge grooves, the two groups of longitudinal grooves 4 are arranged in a staggered mode, wherein an outlet of the feed grooves is closed in the axial direction, and an inlet of the discharge grooves is closed in the axial direction. The outer diameter of the screw thread between the feed chute and the discharge chute is smaller than the diameter of the screw rod, and materials flow into the discharge chute from the feed chute through the smaller outer diameter of the screw thread. When the melted material flows through the mixing section D, shearing heat is generated, the unmelted material can be plasticized, and the gas in the melted material is changed into fine and uniform through shearing and mixing.
The screw depth of the second-order compression section E gradually becomes shallow and is connected with the screw depth of the second-order metering section F in a flat way. The grooves of the second-order metering section F are equal in depth. And setting a second-order compression section E and a second-order metering section F, so that the molten material is plasticized again.
The length of each section on the screw 1 is as follows: the feeding section A is larger than the separation type compression section B, the second-order metering section F is larger than the second-order metering section E is larger than the mixing section D and is larger than the metering section C, wherein the length of the feeding section A is 30-40% of the total length of the screw 1, the length of the separation type compression section B is 24-28% of the total length of the screw 1, and the length of the metering section C is one lead.
Aspect ratio 28 of screw 1 of this example: 1, ensuring That Polyurethane (TPU) materials can be fully melted and plasticized in the screw 1, and if the length-diameter ratio is too small, the Polyurethane (TPU) materials cannot be fully melted and plasticized in the screw 1, so that the product has crystal points and the surface is opaque. The diameter of the screw is 1, phi 20-phi 50mm.
According to the embodiment, the structure of the screw 1 is changed, so that polyurethane plastics can be sufficiently sheared and melted in the screw 1, meanwhile, the stability of continuous production quality is improved, and the product quality is improved.
The foregoing is merely a preferred embodiment of the present utility model, and it should be noted that it will be apparent to those skilled in the art that several modifications and variations can be made without departing from the technical principle of the present utility model, and these modifications and variations should also be regarded as the scope of the utility model.
Claims (8)
1. The utility model provides a special screw rod is extruded to medical pipe of polyurethane medical treatment, includes screw rod and main flight, and main flight sets up on the face of cylinder of screw rod along screw rod length direction, and main flight forms helicoidal groove and main spiral arris, its characterized in that with the screw rod: the screw is sequentially divided into a feeding section, a separation type compression section, a metering section, a mixing section, a second-order compression section and a second-order metering section along the length direction from feeding to discharging, the main screw pitch on the screw is equal, a secondary screw slice which plays a barrier role to separate solid plastic from molten plastic is arranged on the separation type compression section, the outer diameter of the secondary screw slice is smaller than that of the main screw slice, the screw diameter of the separation type compression section is gradually increased, and the length-diameter ratio of the screw is 27:1-29:1.
2. The polyurethane medical catheter extrusion dedicated screw according to claim 1, wherein: the spiral grooves of the separation type compression section are divided into molten-state area spiral grooves and solid-state area spiral grooves by the auxiliary spiral sheets, molten plastic enters the molten-state area beyond the outer diameter of the auxiliary spiral sheets, the width of the solid-state area spiral grooves is gradually narrowed, the depth of the spiral grooves is gradually shallower, the width of the molten-state area spiral grooves is gradually widened, and the depth of the spiral grooves is gradually deepened and then shallower and is leveled with the depth of the metering section spiral grooves.
3. The polyurethane medical catheter extrusion dedicated screw according to claim 1, wherein: a plurality of longitudinal grooves are formed in the cylindrical surface of the screw rod of the mixing section at equal intervals, the longitudinal grooves are divided into two groups of feed grooves and discharge grooves, the two groups of longitudinal grooves are alternately arranged, an outlet of the feed grooves is closed in the axial direction, and an inlet of the discharge grooves is closed in the axial direction.
4. A polyurethane medical catheter extrusion specialized screw as described in claim 3, wherein: the outer diameter of the thread between the feed chute and the discharge chute is smaller than the diameter of the screw rod.
5. The polyurethane medical catheter extrusion dedicated screw according to claim 1, wherein: the depth of the screw groove of the second-order compression section gradually becomes shallow and is connected with the depth of the screw groove of the second-order metering section in a flat manner.
6. The polyurethane medical catheter extrusion dedicated screw according to claim 1, wherein: the grooves of the second-order metering section are equal in depth.
7. The special screw for extruding polyurethane medical catheters according to any one of claims 1 to 6, wherein: the length of each section on the screw rod is as follows: the feeding section is larger than the separation type compression section, the second-order metering section is larger than the second-order compression section, the mixing section is larger than the metering section, the length of the feeding section is 30-40% of the total length of the screw, the length of the separation type compression section is 24-28% of the total length of the screw, and the length of the metering section is one lead.
8. The special screw for extruding polyurethane medical catheters according to any one of claims 1 to 6, wherein: aspect ratio of the screw 28:1, the diameter phi of the screw rod is 20-50 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322049529.XU CN220995399U (en) | 2023-08-01 | 2023-08-01 | Special screw rod is extruded to medical pipe of polyurethane medical treatment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322049529.XU CN220995399U (en) | 2023-08-01 | 2023-08-01 | Special screw rod is extruded to medical pipe of polyurethane medical treatment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220995399U true CN220995399U (en) | 2024-05-24 |
Family
ID=91122110
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202322049529.XU Active CN220995399U (en) | 2023-08-01 | 2023-08-01 | Special screw rod is extruded to medical pipe of polyurethane medical treatment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220995399U (en) |
-
2023
- 2023-08-01 CN CN202322049529.XU patent/CN220995399U/en active Active
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